Engine Idle Is Sporadic! Please Help

cboman777 · October 7th, 2006, 12:23 AM

I own a 89 lx 5.0 with 5-speed tranny. The starter has to crank 5-10 seconds to start. At that time it idles at 2500 rpm's and fluctuates. I've been looking through the posts. Could it be the IAC? What other electrical parts can I clean that may be bad?

itschristorres8 · October 7th, 2006, 12:25 AM

no the if it was the IAC the car would want to stall not go beyond its normal idle rpm to 2500
get a tune up and might be you starter or idk, never heard of that
but not your IAC

cboman777 · October 7th, 2006, 12:28 AM

It happened overnight. One time it was fine next it wasn't. At times I will turn it off waiting for a light. When I try to start it it will sputter and have to try starting it a number of times before it will start.

ChrisJ · October 7th, 2006, 02:12 AM

Check the coils, distributor cap, and rotor button...The also check your plug wires...

Let me know if that helps...If it does not fix it let us know and then we can further diagnose it...

itschristorres8 · October 7th, 2006, 02:16 AM

i was talking to him...and we thought its probably his computer....it has to be reading something wrong
a car reving that high at idle, is not due to regular maintance like oil, air filter changes or any of that

ChrisJ · October 7th, 2006, 02:20 AM

Originally Posted by itschristorres8

i was talking to him...and we thought its probably his computer....it has to be reading something wrong
a car reving that high at idle, is not due to regular maintance like oil, air filter changes or any of that

It could be the idle screw...

There is alot that it can be...

The more details you give the more we can better diagnose it...

302's are alot different then diasgnoseing the newer stangs...You really need alittle bit of expiriance with the 5.0's to really diagnose it...

We have alot of guys on here that know 5.0 inside and out...

itschristorres8 · October 7th, 2006, 02:24 AM

this is what he gave me..
when i first got the car it would start withing 1-2 seconds of cranking
now it takes 5-10 seconds and the idle is way high
it didn't get progressivly worse it was one extreme to the other

sometimes at a light I will stop the engine so it doesn't rev high for an extended amount of time

and when I try to restart it will sputter and not start. I have to try to start it approximately 10 times before it will stay running

I have the bbk cold air and cleaned and oiled the filter within 2 weeks. spark plugs and oil within a few months
The starter is cranking properly. Is it possible it could be the computer?

thats what he gave me when i tlked with him,...i deleted the screen name for privacy issues incase he didnt want his screen name out...all that was his words

ChrisJ · October 7th, 2006, 02:37 AM

Yeah it could be a cracked coil, distributor cap, or a bad rotor button...There are other things as well...

ken5_0 · October 7th, 2006, 02:23 PM

Reving to 2500? Sounds almost like a vac leak after the MAF. Oh and Chris Torres... NICE BUTT

Bill · October 8th, 2006, 12:34 AM

i say check your computer for codes. thats the best place to start IMO.

but you only have this hard starting when the car is warm???

when this happens again try stepping on the gas to get it to start. thats the only way i could get mine to start with out having to crank it for ever.

turned out it was my Coolant Temp. sensor went bad. fix that and hadnt had problems since.

but check for codes. use this link if you dont have a Scanner. i used it multiple times and it works great. just need a wire and sit in your car and count the engine light flashes.

http://www.mustangworks.com/articles...-iv_codes.html

ken5_0 · October 8th, 2006, 10:29 AM

the reving also could be the coolant temp sensor. Good call there. If the sensor is bad it could curve the fuel map to run rich.

89StangGT · October 8th, 2006, 02:55 PM

wow dude my 89 Fox is doing exacly the same thing i was just about to post about it. when i first bought it, it fired up right away, now it cranks for a while before it starts, and it revs about 2300 for a coulple mins then idles down to about 900 and fluxuates. i turned the idle up a bit because it was at like 400 and it almost died at lights, and i put a cold air intake on it too. other than that i havnt done anything and dont know why its doing this. its really worrying me though.

Bill · October 8th, 2006, 11:13 PM

Originally Posted by ken5_0

the reving also could be the coolant temp sensor. Good call there. If the sensor is bad it could curve the fuel map to run rich.

yep. when ever it would start i would get a big thing of black smoke out the pipes.

engine code said ECT. replaced that and no problems since.

got the coolant temp sensor at auto zone for 23.00.

KJeezy · October 9th, 2006, 03:10 PM

Friend's 88 did the same thing. Idled very high, flutuated just like it was always trying to warm up. He hasn't changed the sensor yet, but that is what we were going to do next. This was after we were told to change the sensor on the distributor as well as the TPS.

October 7th, 2006, 12:23 AM	#1
cboman777 Newbie Join Date: Oct 2006 Posts: 2 iTrader: 0 reviews	Engine Idle Is Sporadic! Please Help I own a 89 lx 5.0 with 5-speed tranny. The starter has to crank 5-10 seconds to start. At that time it idles at 2500 rpm's and fluctuates. I've been looking through the posts. Could it be the IAC? What other electrical parts can I clean that may be bad?

October 7th, 2006, 12:25 AM	#2
itschristorres8 Banned 00 V6 & 09 GT 13.37@104.4mph--BONE stock GT Join Date: Aug 2006 Location: south florida Posts: 15,806 iTrader: 2 reviews	no the if it was the IAC the car would want to stall not go beyond its normal idle rpm to 2500 get a tune up and might be you starter or idk, never heard of that but not your IAC __________________ [SIGPIC][/SIGPIC] Acmillr loves me

October 7th, 2006, 02:12 AM	#4
ChrisJ RLY SRS Join Date: Aug 2005 Location: Ft. Meade, MD Posts: 38,220 Blog Entries: 4 iTrader: 10 reviews	Check the coils, distributor cap, and rotor button...The also check your plug wires... Let me know if that helps...If it does not fix it let us know and then we can further diagnose it... __________________ 2008 Acura TL Type-S - 2008 EB Ford Expedition - 2002 Boosted GT - Sold Facebook Google+

October 7th, 2006, 02:16 AM	#5
itschristorres8 Banned 00 V6 & 09 GT 13.37@104.4mph--BONE stock GT Join Date: Aug 2006 Location: south florida Posts: 15,806 iTrader: 2 reviews	i was talking to him...and we thought its probably his computer....it has to be reading something wrong a car reving that high at idle, is not due to regular maintance like oil, air filter changes or any of that __________________ [SIGPIC][/SIGPIC] Acmillr loves me

October 7th, 2006, 02:24 AM	#7
itschristorres8 Banned 00 V6 & 09 GT 13.37@104.4mph--BONE stock GT Join Date: Aug 2006 Location: south florida Posts: 15,806 iTrader: 2 reviews	this is what he gave me.. when i first got the car it would start withing 1-2 seconds of cranking now it takes 5-10 seconds and the idle is way high it didn't get progressivly worse it was one extreme to the other sometimes at a light I will stop the engine so it doesn't rev high for an extended amount of time and when I try to restart it will sputter and not start. I have to try to start it approximately 10 times before it will stay running I have the bbk cold air and cleaned and oiled the filter within 2 weeks. spark plugs and oil within a few months The starter is cranking properly. Is it possible it could be the computer? thats what he gave me when i tlked with him,...i deleted the screen name for privacy issues incase he didnt want his screen name out...all that was his words __________________ [SIGPIC][/SIGPIC] Acmillr loves me

October 7th, 2006, 12:28 AM	#3
cboman777 Newbie Join Date: Oct 2006 Posts: 2 iTrader: 0 reviews	It happened overnight. One time it was fine next it wasn't. At times I will turn it off waiting for a light. When I try to start it it will sputter and have to try starting it a number of times before it will start.

October 7th, 2006, 02:37 AM	#8
ChrisJ RLY SRS Join Date: Aug 2005 Location: Ft. Meade, MD Posts: 38,220 Blog Entries: 4 iTrader: 10 reviews	Yeah it could be a cracked coil, distributor cap, or a bad rotor button...There are other things as well... __________________ 2008 Acura TL Type-S - 2008 EB Ford Expedition - 2002 Boosted GT - Sold Facebook Google+

October 7th, 2006, 02:23 PM	#9
ken5_0 Regular 1990 GT Convert Join Date: Aug 2006 Location: Prescott WI Posts: 203 iTrader: 0 reviews	Reving to 2500? Sounds almost like a vac leak after the MAF. Oh and Chris Torres... NICE BUTT

October 8th, 2006, 12:34 AM	#10
Bill Hardcore Enthusiast Join Date: Aug 2005 Posts: 1,327 iTrader: 0 reviews	i say check your computer for codes. thats the best place to start IMO. but you only have this hard starting when the car is warm??? when this happens again try stepping on the gas to get it to start. thats the only way i could get mine to start with out having to crank it for ever. turned out it was my Coolant Temp. sensor went bad. fix that and hadnt had problems since. but check for codes. use this link if you dont have a Scanner. i used it multiple times and it works great. just need a wire and sit in your car and count the engine light flashes. http://www.mustangworks.com/articles...-iv_codes.html __________________ Too often, We lose sight of life's simple pleasures. Remember, when someone annoys you it takes 42 muscles in your face to frown, BUT, it only take 4 muscles to extend your arm and bitch-slap that Mother@#?!&! upside the head!!

October 8th, 2006, 10:29 AM	#11
ken5_0 Regular 1990 GT Convert Join Date: Aug 2006 Location: Prescott WI Posts: 203 iTrader: 0 reviews	the reving also could be the coolant temp sensor. Good call there. If the sensor is bad it could curve the fuel map to run rich.

October 8th, 2006, 02:55 PM	#12
89StangGT Moderator SVT Cobra Mustang Join Date: Aug 2006 Location: Toledo, Ohio Posts: 1,876 iTrader: 0 reviews	wow dude my 89 Fox is doing exacly the same thing i was just about to post about it. when i first bought it, it fired up right away, now it cranks for a while before it starts, and it revs about 2300 for a coulple mins then idles down to about 900 and fluxuates. i turned the idle up a bit because it was at like 400 and it almost died at lights, and i put a cold air intake on it too. other than that i havnt done anything and dont know why its doing this. its really worrying me though. __________________ There's a reason Ford codenamed them the Terminator

October 9th, 2006, 03:10 PM	#14
KJeezy Newbie Join Date: Sep 2006 Posts: 49 iTrader: 0 reviews	Friend's 88 did the same thing. Idled very high, flutuated just like it was always trying to warm up. He hasn't changed the sensor yet, but that is what we were going to do next. This was after we were told to change the sensor on the distributor as well as the TPS.

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